Rotary mechanical translating device

ABSTRACT

A rotary mechanical translating device may be defined as a purely mechanical device which transfers power from a prime mover to a load as a magnified function of a displacement at its input connection. The device exhibits a power gain and may be employed to produce mechanical amplification. A change in angular velocity of its input will result in a change in the angular velocity of its output.

finite St tes ate t Watson 1 Nov. 6, 1973 [54] ROTARY MECHANICALTRANSLATING 2,384,776 9/1945 Tmfimov 74/689 DEVICE 2,665,596 1/1954Varble 74 756 3,046,814 7/1962 Soehrman 74/689 Inventor: Thomas Watson,2720 3,299,741 1/1967 Twiford 74/682 Goyer St., Apt. 24, Montreal,3,318,172 5/1967 Cummins 74/682 Quebec, Canada 22 Filed; 3 0 PrimaryExaminerC. J. Husar AztorneyThomas A. W. K. Watson [211 Appl. No; 94,819

I 57] ABSTRACT 52 us. c1. 74/682 A rotary mechanical device may bedefi'wd 51 1111.131. F1611 37/06 as Purely mechanical device which *ii[58] Field Of Search 74/687, 682, 689, from a Primg move a as a magmfiedf 74/675 of a displacement at its input connection. The device exhibitsa power gain and may be employed to produce [56] Reierences Citedmechanical arlrliplification. 3 change liln angular velocity of itsinput wi resu t in a c ange int c angu ar ve oclty UNITED STATES PATENTSof itsoutput. 2,422,343 6/1947 Duer 74/685 X 2,771,286 11/1956 Clark,Jr. 415/30 8 Claims, 8 Drawing Figures PMENTEURUY 6 ma 3.770.879 arm 1c? 3 774m aux/7.10m

PATENTEDHUY 6 I975 3.770.879

SHEET 3 BF 3 7160mm (HUM 11 m 1 ROTARY MECHANICAL TRANSLATING DEVICE Inits simplest form it comprises an input differential driving an outputdifferential through a rotary unidirectional coupler or unidirectionalrotary releaser or self locking rotary coupler. An input connection isattached to said input differential and an output connection is attachedto said output differential. Both differentials are driven from a primemover. The input differentials drive, to the output differential, andthe drive from the prime mover, to the output differential, cancels eachother. This results in no output, when the input is held stationary.Rotation of the input in the direction that reduces the inputdifferentials drive, to the output differential, unbalances the system.This results in the device transferring power from the prime mover tothe output connection.

The unidirectional coupler, which may take the form of a worm and wormgear, serves as a means against which the output differential may react,so as to develop output torque, and as a means of preventing said torquefrom appearing in the input. The output differential tends to drive theunidirectional coupler in the same direction that it is actually drivenby the input differential. A modest amount of effort is required torotate the unidirectional coupler in this direction, hence little effortis required to drive the input.

This disclosure relates to several rotary mechanical translatingdevices, all comprising systems of differentials, gears and othermechanical devices. Several systems are presented, each of which hasdifferent characteristics.

In one embodiment the spider of a first differential is driven by aprime mover and its first end gear is connected to the output shaft. Itssecond end gear is coupled to a first worm gear, which in turn mateswith a first worm. The first end gear of a second differential drivessaid first worm. The spider of said second differential is also drivenby the prime mover. The second end gear of said second differential isconnected to a second worm gear which mates with a second worm. Thefirst differentials spider is directly driven from the prime mover andits second end gear is indirectly driven from the prime mover throughthe second differential. The ratio and direction of these two drives tothe first differential is such that a balance occurs, resulting in zerorotation of the output shaft. This condition occurs when said secondworm and worm gear are held stationary. When said second worm is rotatedan unbalance occurs resulting in rotation of the output shaft.

This particular rotary mechanical translating device is unidirectional.It may be operated in the reverse direction by reversing the directionof the prime mover. In order to produce amplified bidirectional rotationat the output, a third differentials first end gear may be attached in asimilar manner to the second worm and worm gear. Its spider should alsobe driven by the prime mover. The drive ratios are selected such thatthe second differential is over driven by the prime mover. the thirddifferential is driven and drives the second differential so as tocancel its over drive. A third worm gear is attached to the second endgear of the third differential and co-operates with a third worm. Thethird worm acts as the input and it may be driven in either direction,producing rotation in the output in corresponding directions.

The second worm gear will always drive against the second worm whichrotates in one direction only. This is the same direction as it istended to be driven by the second worm gear. Little effort is thenrequired to drive the second and third worm and the third differential.The system gain however will be more in the direction in which the thirddifferential drives the third worm gear. When the third worm drivesagainst the third worm gear, more effort is required. Amplificationhowever occurs in both directions.

A balanced rotary mechanical translating device in which the input maydrive the output with equal effort in both directions may be constructedfrom a system of four differentials and four worm and worm gears. Inthis arrangement the output differential derives its power from twoother differentials which are driven from a prime mover. The fourthdifferential controls the system balance and is attached to the inputconnection.

Two or more of the above rotary mechanical translating devices may becascaded to provide greater amplification. They may be employed toprovide mechanical amplification and position control etc.

The primary objective is to provide a rotary mechanical translatingdevice which uses only mechanical means to produce amplification.Another objective is to provide an improved means for controllingmechanical energy. Another objective is to provide a unidirectionalrotary mechanical translating device. Still another objective is toprovide a bidirectional rotary mechanical translating device. Anotherobjective is to provide a means of coupling the rotary mechanicaltranslating devices together so as to produce more amplification.Further objectives and advantages will become apparent in the followingdescriptions.

FIG. 1 is a schematic diagram of a unidirectional rotary mechanicaltranslating device.

FIG. 2 is a side view of a unidirectional rotary mechanical translatingdevice.

FIG. 3 is a plan view of the unit shown in FIG. 2.

FIG. 4 is a schematic diagram ofa two stage mechanical amplifier.

FIG. 5 is a schematic diagram of a bidirectional rotary mechanicaltranslating device.

FIG. 6 is a schematic of a balanced bidirectional rotary mechanicaltranslating device.

FIG. 7 is a schematic diagram of an alternate input for the balancedrotary mechanical translating device.

FIG. 8 is a schematic diagram of the rotary mechanical translatingdevice in its simplest form.

FIG. 1 shows differentials 1 and 10 with their spider gears 2 and 11respectively meshed and driven by gear 16. Gear 16 is connected to shaft17 which is driven by an external prime mover. One of the end gears ofdifferential l is connected to the output shaft 3 and the other end gearis connected to shaft 4. Shaft 4 is connected to worm gear 5 whichco-operates with worm 6, and in turn is connected to bevel gear 7. Bevelgear 8 meshes with gear 7 and is connected to shaft 9 which in turn isconnected to one of the end gears of differential 10. The other end gearof differential 10 is connected to shaft 12 to which is connected wormgear 13. Worm 14 co-operates with worm gear 13 and is connected to theinput shaft 15.

The arrows show the relative direction of rotation of the shafts.Reversing the direction of rotation of the prime mover will reverse thedirection of operation of the unidirectional rotary mechanicaltranslating device.

When the input shaft 15 is not rotated it causes worm gear 13 to lockagainst worm 14, hence locking shaft 12. Shaft 9 is then driven bydifferential at its maximum velocity driving gear 8 which drives gear 7and in turn worm 6. Rotation of gear 6 causes rotation of gear 5, henceshaft 4. Shaft 4 is driven in the same direction and at the samevelocity by worm gear 5, as it is driven by the end gear of differential1 to which it is connected. This causes a balance condition to existwhich results in zero rotation of the output shaft.

Rotation of the input shaft in the direction shown results in worm 14releasing worm gear 13. Gear 13 is driven against gear 14 and hencelittle effort is required to rotate the input shaft in the direction inwhich it is tended to be driven. The rotation of worm gear 13 in thedirection shown allows shaft 12 to rotate resulting in the slowing downof shaft 9 as a consequence of differential action. This slows downshaft 4 and upsets the balance condition in differential 1 resulting inrotation of the output shaft 3.

When the input shaft 15 is rotated at a sufficiently high enoughvelocity to balance out the rotation of shaft 9, worm gear 5, worm 6 andshaft 4 stall. The output shaft 3 is then driven at full velocity by theprime mover through differential 1, as a result of the stalling of shaft4, connected to one of its end gears. Disconnecting worm 14 and allowingworm gear 13 to rotate freely would have the same effect.

Rotation of the output shaft 3 occurs only when the input shaft 15 isrotated. The prime mover supplies the power that drives the output shaft3. Shaft 15 acts to control the speed at which the prime mover drivesshaft 3. Since little effort is required to rotate the input shaft andthe output shaft is driven by the prime mover, mechanical amplificationresults. Gear ratios may be selected to provide the required amount ofrotation of the output shaft for given angular changes in the inputshaft. The gear train comprising gears 5, 6, 7 and 8 have a combinedratio of unity, hence shaft 4 and 9 rotate at the same volocity. Whenthere is no input to shaft 15, shaft 12 is held stationary anddifferentials 1 and it) rotate shafts 4 and 9 respectively at twice theangular velocity of their driven spider gears.

Rotation of the input shaft backwards or at a speed greater than thatrequired to stall shaft 4 will require considerable effort and is beyondthe limit of the useful range of amplification of the device. In thecase of bidirectional rotary mechanical translating devices, operationin the reverse direction will be satisfactory up to the speed which willdevelop a stalled condition within the unit.

The input worm and worm gears may be eliminated and the shaft 12 used asan input shaft provided that it is connected to a device which resistsits free rotation. Little force is required to prevent the rotation ofshaft 12.

The connections to the differentials may be interchanged provided thegear ratios are properly selected. A differential is a rotarydifferential means having three connections. each connection havinginterrelated and variable angular velocities with respect to each other.The terms first connection. second connection and third connection shallhe used to designate these mechanical connections without regard towhich part of the differential or differential means to which it isconnected. Bevel gear and other types of differentials may be employedand the foregoing terminology shall still be applicable even though theydo not necessarily have end gears and a spider. Worm gears could bereplaced by other rotary undirectional couplers, often referred to ashaving self locking characteristics, such as twin worm gears.

F163. 2 and 3 show the construction of the rotary mechanical translatingdevice depicted in the schematic diagram of FIG. 1. Bearing blocks 52,65, 69, 75, 88, 92 and 95 are all mounted to base 50. An output shaft 51runs in bearing 52 and bearing 53 mounted to housing 54 of the outputdifferential 76. A bevel gear 62 is fastened to shaft 51 and meshes withbevel gear 61 and 63 mounted on stub axels 57 and 59 which rotates inbearings 55 and 58 respectively mounted in housing 54. A bevel gear 60meshes with gears 61 and 63 and is fastened to shaft 66 which runs inbearing 56 mounted on the spider gear 64 and bearing 65. Housing 54 isattached to the spider gear 64. A worm gear 67 is fixed to shaft 66. Aworm 68 on shaft 71 which rotates in bearing 69 meshes with worm gear67. A bevel gear 72 is attached to shaft 71 and co-operates with bevelgear 73 on shaft 74. Shaft 74 runs in bearing 75 and bearing 76 mountedon spider gear 77 to which is mounted housing 81. A bevel gear 84 isfastened to shaft 74 and meshes with bevel gears 85 and 87 mounted onstub axels 79 and 82 which run in bearings 78 and 83 respectively.Bearings 78, and 83 are mounted in housing 81. Bevel gear 86 meshes withgears and 87 and is fastened to shaft 89 which runs in bearings 80 and88. A worm gear 90 is fastened to shaft 89 and meshes with worm 91. Worm91 is fixed to input shaft 93 which runs in bearing 92. A gear 94 isattached to the prime mover input shaft 96 which runs in bearing 95.Gear 94 drives spider gear 77 of the input differential 97 which in turndrives the spider gear 64.

An external prime mover applies power to the input shaft 96. The inputshaft 93 controls the rotation of the output shaft 51 which derives itspower from shaft 96.

FlG. 4 shows a schematic diagram of two cascaded rotary mechanicaltranslating device 101 and 104. A prime mover is connected to shaft 102and 105 of rotary mechanical translating device 1111 and 104respectively. The output shaft 103 of rotary mechanical translatingdevice 101 is connected to the input shaft 107 of rotary mechanicaltranslating device 164. The input shaft 100 of rotary mechanicaltranslating device 101 controls the output shaft 106 of the rotarymechanical translating device 104.

FIG. 5 shows a schematic diagram of a bidirectional rotary mechanicaltranslating device, An input shaft 110 is coupled to worm 111 whichmeshes with a worm gear 112 on shaft 113. Shaft 113 is connected to anend gear of the input differential 114. The other end gear ofdifferential 114 is connected to shaft 116 to which is fixed bevel gear117 which meshes with bevel gear 118. Bevel gear 118 is coupled to worm119 which meshes with worm gear 120 attached to shaft 121. Shaft 121 isconnected to one of the end gears of differential 123 whose other endgear is connected to shaft 124. A bevel gear 125 is attached to shaft124 and meshes with bevel gear 126 which is coupled to worm 127. Wormgear 128 meshes with worm 127 and is fixed to shaft 129. Shaft 129 iscoupled to one of the end gears of the output differential 130. Anoutput shaft 134 is connected to the other end gear of differential 130.Power is derived from an external prime mover connected to the powerinput shaft 133. Shaft 133 is fixed to gear 132 which meshes with thespider gear 131 of differential 130. Spider gear 131 also meshes withspider gear 122 on the intermediate differential 123 which in turnmeshes with spider gear 115 on differential 114. The output differential130 is driven by the prime mover and shaft 129. The speed and directionof the two drives to the differential 130 is such that a balancecondition occurs resulting in zero rotation of the output shaft. Theratio of gears 125, 126, 127 and 128 is made greater than unity whichwill tend to overdrive shaft 129. However, the rotation of shaft 121just compensates for this overdrive. Shaft 121 rotates at a speedcontrolled by the system comprising differential 114 and gears 117, 118,119 and 120. The overall system gear ratios are selected to just balanceout any rotation of the output shaft 134.

Rotation of the input shaft 110 in one direction decreases the speed ofrotation of shaft 116. Rotation of the input shaft 110 in the oppositedirection increases the speed of shaft 116. A limiting condition occurswhen the input shaft 110 drives shaft 116 to a stall. A substantialamount of input drive will be required beyond this limit, as a result ofthe input power appearing in the output.

Another limiting condition occurs when the input shaft 110 drives shaft124 to a stall. Throughout the useful range of amplification of thedevice, gear 120 rotates in the same direction being driven by thedifferential 123. Little effort is required to rotate worm 119 throughout this range. The output shaft 134 rotates in one direction when shaft129 rotates below the speed required to produce the balance and theoutput shaft rotates in the opposite direction when shaft 129 rotatesfaster than the speed required to produce the balance. Rotation of theinput shaft 110 in either direction upsets this balance, resulting inamplification in both directions.

FIG. 6 shows a balanced bidirectional rotary mechanical translatingdevice which requires equal input in both directions. An output shaft150 is fixed to gear 151 which is driven by spider gear 152 of theoutput differential 153. Shafts 154 and 155 are connected to the wormgears 159 and 157 respectively and to the end gears of differential 153.Worms 158 and 156 are connected to shaft 160 and 165 and mesh with wormgears 159 and 157 respectively. Shafts 160 and 165 are connected to anend gear of differentials 161 and 166 respectively. Shafts 163 and 168are coupled to the end gears of differentials 161 and 166 respectively.Worm gears 171 and 177 which are fixed to shafts 163 and 168respectively, mesh with worms 172 and 178 respectively. Shafts 175 and176 are fixed to worms 172 and 178 respectively, and are coupled to theend gears of the input differential 170. The spider gear 169 of differential 170 is driven by the gear 173 on the input shaft 174. Theprime mover input shaft 179 is fixed to gear 164 which meshes with gear180 and spider gear 167 of differential 166. Gear 180 meshes with thespider gear 162 of differential 161.

When the input shaft is stationary, shafts 163 and 168 remainstationaryv Symetrical drive in opposite directions is applied todifferentials 161 and 166 resulting in shafts 154 and 155 rotating withequal velocities in opposits directions. This results in a balancecondition occurring in the differential 153. In order to rotate theoutput shaft this balance must be upset. Rotation of shaft 175 or 176will produce an unbalance causing the output shaft to rotate. Thedifferential when rotated in one direction will activate shaft and inthe other direction, shaft 176. One shaft is difficult to rotate in onedirection and the other in the opposite direction, the differentialselects the shaft exhibiting the lease resistance to rotation.

The device is symetrical, therefore the sense of unbalance determinesthe direction of rotation of the output. Limiting conditions occur whenshafts 160 and 165 are driven to a stall by the input.

FIG. 7 shows an alternate input arrangement. An input shaft is fixed toa gear 184 which drives gear 183 attached to shaft 182. Shafts 188 and187 are attached to ratchets 181 and 186 respectively, which in turn arefixed to shaft 182. Rotation of shaft 182 in one direction engagesratchet 181, which results in the rotation of shaft 188. Rotation ofshaft 182 in the opposite direction results in the engaging of ratchet186, thus causing rotation of shaft 187. Shafts 188 and 187 may becoupled to worms 1'72 and 178 of FIG. 6 eliminating the need of theinput differential 170.

FIG. 8 shows the rotary mechanical translating device in a very simpleform, comprising a power input shaft or connection 201, fixed to a bevelgear 200 which meshes with spider gear 202 of the output differential203. An output shaft or connection 204 is joined to differential 203. Ashaft 205 also extends from differential 203 and is fixed to a worm gear206 meshed with a worm 207. Worm 207 is fixed to shaft 208 which isconnected to one of the end gears of the input differential 209. Theother end gear of differential 209 is connected to the input shaft orconnection 211. The spider gear 210 of the input differential 209 ismeshed with spider gear 202 of differential 203.

The operation of this device is similar to that given for FIG. 1. N0input worm and worm gear are shown since it is not required, when theinput shaft is prevented from freely rotating. The bevel gears 7, 8, 72,73, 117 and 118 in FIGS. 1, 3 and 5 may be eliminated in othervariations of the device, as they are not fundamental to its operation.

Normally a single prime mover would be connected to the translatingdevice, however it is possible to connect separate prime movers,although not preferable, to each differential requiring power.

In the case of the rotary unidirectional rotary releasers or selflocking rotary couplers, the input refers to the connection of thedevice which accepts power and the output connection refers to theconnection which delivers power. In all these devices the output shaftor connection cannot be rotated unless the input shaft is rotated, hencethey have a rotary releasing action, in as much as the rotation of theinput releases a rotary moment of force applied to the output. Also theoutput locks against the input, exhibiting a self lockingcharacteristic. In the worm and worm gear combination the worm acts asthe input and the worm gear the output. The worm gear is not capable ofdriving the worm but the worm is capable of driving the worm gear. Inoperation in a rotary translating device the worm acts to release theworm gear.

A twin worm gear comprises two meshed helical screws. One helical screwhas a fine pitch and the other a course pitch wound in the oppositedirection. Since each screw has a different lead angle, they do not haveparallel shafts, hence they may be used in conjunction with bevel orhelical gears, in order to make their shafts parallel. It has a selflocking characteristic similar to that of a worm and worm gear, it willalso act to provide a releasing action.

The translating device as shown in FIG. 8 is basic to all forms of thedevice. It is basic to the devices shown in FIGS. 1, 2, 3, and 6. In thecase of FIG. 6 the drive to differential 153 is obtained through one ofthe worm gears which supplies power to it from a prime mover. The otherworm and worm gear acts as a unidirectional coupler. Since the system issymmetrical the worm and worm gear through which input rotation istransmitted, is to be considered as the one that acts as aunidirectional coupler.

it is also not necessary to completely balance any of the translatingdevices. When a prime mover drives the device's power input connection,it could develop an output on its power output connection, even thoughits control input connection is not rotated. When the input is rotatedit would change the speed of the output.

The foregoing disclosure is illustrative and it is understood thatchanges may be made to the embodiments contained herein withoutdeparting from the scope and spirit of this invention.

I claim:

1. A rotary mechanical translating device comprising a first and asecond differential each having a first, a second and a third connectionmeans, a self locking rotary coupler having an output connection meansconnected to the first connection means of the first differential, andsaid self locking rotary coupler having an input connection meansconnected to the first connection means of the second differential.

2. A rotary mechanical translating device as claimed in claim 1,comprising a second self locking rotary coupler having an outputconnection means connected to the third connection means of the seconddifferential.

3. A mechanical amplifier comprising a first and a second differentialeach having a first, a second, and a third connection means, a selflocking rotary coupler having an output connection means connected tothe first connection means of the first differential, said self lockingrotary coupler having an input connection means connected to the firstconnection means of the second differential, the second connection meansof the first and second differentials connected to a prime mover, thethird connection means of the first differential connected to a load,and the third connection means of the second differential connected toan input control means.

4. A rotary mechanical translating device comprising a first, and asecond self locking rotary coupler each having an input and an outputconnection means, a first differential connected to the outputconnection means of the first self locking rotary coupler, a seconddifferential connected between the input connection means of the firstself locking rotary coupler and the output connection means of thesecond self locking rotary coupler, and a third differential connectedto the input connection means of the second self locking rotary coupler.

5. A rotary mechanical translating device as claimed in claim 4,comprising a third self locking rotary coupler having an input and anoutput connection means, in which the third differential is connectedbetween the output connection means of the third self locking rotarycoupler and the input connection means of the second self locking rotarycoupler.

6. A rotary mechanical translating device comprising a first, a second,a third and a fourth self locking rotary coupler each having an inputand an output connection means, a first differential connected betweenthe output connection means of the first and fourth self locking rotarycouplers, a second differential connected between the input connectionmeans of the first self locking rotary coupler and the output connectionmeans of the second self locking rotary coupler, and a thirddifferential connected between the output connection means of the thirdself locking rotary coupler and the input connection means of the fourthself locking rotary coupler.

7. A rotary mechanical translating device as claimed in claim 6,comprising a fourth differential connected between the input connectionmeans of the second and third self locking rotary couplers.

8. A rotary mechanical translating device as claimed in claim 6,comprising a first and a second ratchet each having an input connectionmeans connected to each other; the first ratchet having an outputconnection means connected to the input connection means of the secondself locking rotary coupler, the second ratchet poled for engagement inthe opposite direction to the first ratchet and having an outputconnection means connected to the input connection means of the thirdself locking rotary coupler.

1. A rotary mechanical translating device comprising a first and asecond differential each having a first, a second and a third connectionmeans, a self locking rotary coupler having an output connection meansconnected to the first connection means of the first differential, andsaid self locking rotary coupler having an input connection meansconnected to the first connection means of the second differential.
 2. Arotary mechanical translating device as claimed in claim 1, comprising asecond self locking rotary coupler having an output connection meansconnected to the third connection means of the second differential.
 3. Amechanical amplifier comprising a first and a second differential eachhaving a first, a second, and a third connection means, a self lockingrotary coupler havIng an output connection means connected to the firstconnection means of the first differential, said self locking rotarycoupler having an input connection means connected to the firstconnection means of the second differential, the second connection meansof the first and second differentials connected to a prime mover, thethird connection means of the first differential connected to a load,and the third connection means of the second differential connected toan input control means.
 4. A rotary mechanical translating devicecomprising a first, and a second self locking rotary coupler each havingan input and an output connection means, a first differential connectedto the output connection means of the first self locking rotary coupler,a second differential connected between the input connection means ofthe first self locking rotary coupler and the output connection means ofthe second self locking rotary coupler, and a third differentialconnected to the input connection means of the second self lockingrotary coupler.
 5. A rotary mechanical translating device as claimed inclaim 4, comprising a third self locking rotary coupler having an inputand an output connection means, in which the third differential isconnected between the output connection means of the third self lockingrotary coupler and the input connection means of the second self lockingrotary coupler.
 6. A rotary mechanical translating device comprising afirst, a second, a third and a fourth self locking rotary coupler eachhaving an input and an output connection means, a first differentialconnected between the output connection means of the first and fourthself locking rotary couplers, a second differential connected betweenthe input connection means of the first self locking rotary coupler andthe output connection means of the second self locking rotary coupler,and a third differential connected between the output connection meansof the third self locking rotary coupler and the input connection meansof the fourth self locking rotary coupler.
 7. A rotary mechanicaltranslating device as claimed in claim 6, comprising a fourthdifferential connected between the input connection means of the secondand third self locking rotary couplers.
 8. A rotary mechanicaltranslating device as claimed in claim 6, comprising a first and asecond ratchet each having an input connection means connected to eachother; the first ratchet having an output connection means connected tothe input connection means of the second self locking rotary coupler,the second ratchet poled for engagement in the opposite direction to thefirst ratchet and having an output connection means connected to theinput connection means of the third self locking rotary coupler.